On-highway trucks having manual transmissions are often used to move payloads over long distances. The manual transmissions used in on-highway trucks can have any number of gears and typically have 10,13 or 18 gears or speeds. Generally, a stick shift is used in automobiles to change between gears of a five speed manual transmission by moving the stick shift to a position corresponding to the desired gear. However, with so many more gears used in on-highway trucks, it is common for a single stick position to be used for more than one gear.
Conventionally, a shuttle switch and/or a range switch is often used to shift between gears sharing the same stick shift position. For example, on a manual transmission having ten gears and a shuttle switch, the stick shift only moves through five positions in order to downshift from the tenth gear through all of the gears to the first gear. When the transmission is in tenth gear, the operator downshifts into ninth gear while the engine is below the downshift speed by operating the shuttle switch. To downshift into eighth gear while currently in ninth gear, the driver shifts into eighth gear by moving the stick shift into the corresponding position when the engine speed is below the downshift speed. This pattern generally continues until the driver moves the stick shift into the first position and operates the shuttle switch to shift into first gear.
Currently, traffic disturbances are often due to a driver slowing down to below the downshift speed before shifting into a lower gear while going up a hill. Traffic disturbances can also occur due to a driver slowing down to below the downshift speed before shifting into a lower gear to accelerate quickly enough to pass a slow moving car merging into traffic or to accelerate enough to turn into another lane at a speed consistent with the existing flow of traffic in the other lane. In these examples, the truck driver may cause a traffic disturbance by failing to operate the truck properly.
Typically, the driver must slow the truck down before shifting into a lower gear because the highest allowed downshift speed is typically set at an engine speed desirable for driving on an open highway. However, the downshift speed for driving on an open highway is generally much lower than the downshift speed desired in high traffic situations similar to the examples above. Although the shift stick could have a position for each gear or the downshift speeds could be set at higher speeds, these could potentially make the truck substantially more difficult to operate.
Currently, the truck driver must ensure that the truck is properly operated to prevent traffic disturbances. In the normal operation of a truck, many events are occurring simultaneously. This increases the potential for driver error, including the risk of incorrectly operating the truck by not having the most desired gear engaged at the proper time.
The present invention is directed to overcoming one or more of the problems as set forth above.